/* ==========================================================================
   亿百CN · 共享外壳样式  /assets/site.css
   索引档案室视觉：炭黑底 + 数字蓝主线 + 暖橙标签 + 脉冲绿状态
   ========================================================================== */

/* ---------- reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 88px;
}

body,
h1, h2, h3, h4, h5, h6,
p, figure, blockquote, dl, dd, ol, ul {
  margin: 0;
}

ol, ul { padding: 0; list-style: none; }

img, picture, svg, video {
  display: block;
  max-width: 100%;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

/* ---------- tokens ---------- */
:root {
  --charcoal-base: #0A0C10;
  --panel-slate: #12161C;
  --digital-blue: #1E5AFF;
  --digital-blue-deep: #1748D6;
  --warm-orange: #FF6B35;
  --pulse-green: #4CFF8A;
  --screen-white: #F5F7FF;
  --cold-white: #EDEFF5;
  --index-gray: #8A93A6;
  --hairline: #2A3140;
  --light-blue: #7FA6FF;

  --rail-w: 88px;
  --header-h: 64px;
  --shell-max: 1480px;

  --radius: 2px;
  --shadow-card: 0 1px 0 rgba(255, 255, 255, .04), 0 20px 40px -32px #000;
  --shadow-drawer: 0 24px 48px -24px #000;

  --mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
  --sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --serif: "Source Han Serif SC", "Noto Serif SC", "Songti SC", Georgia, "Times New Roman", serif;
}

/* ---------- base ---------- */
body {
  background-color: var(--charcoal-base);
  background-image:
    linear-gradient(rgba(245, 247, 255, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245, 247, 255, .035) 1px, transparent 1px);
  background-size: 64px 64px;
  background-attachment: fixed;
  color: var(--cold-white);
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 500;
  line-height: 1.9;
  letter-spacing: .005em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  color: #fff;
  font-weight: 900;
  line-height: 1.22;
  letter-spacing: -.012em;
}

h1 { font-size: clamp(32px, 5.4vw, 64px); }
h2 { font-size: clamp(26px, 3.6vw, 40px); }
h3 { font-size: clamp(20px, 2.4vw, 28px); }
h4 { font-size: 19px; }

p { max-width: 42em; margin-bottom: 1.1em; }
p:last-child { margin-bottom: 0; }

a { color: var(--light-blue); text-decoration: none; }
a:hover { color: #fff; }

strong, b { font-weight: 900; color: #fff; }

code, kbd, samp {
  font-family: var(--mono);
  font-size: .92em;
  letter-spacing: .02em;
  color: var(--pulse-green);
}

::selection { background: var(--digital-blue); color: #fff; }

:focus-visible {
  outline: 2px solid var(--pulse-green);
  outline-offset: 2px;
  border-radius: var(--radius);
}

/* ---------- skip link ---------- */
.yb-skip {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  padding: 12px 20px;
  background: var(--digital-blue);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .04em;
  transform: translateY(-130%);
  transition: transform .18s ease;
}
.yb-skip:focus { transform: translateY(0); color: #fff; }

/* ==========================================================================
   头部
   ========================================================================== */
.yb-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(10, 12, 16, .93);
  border-bottom: 1px solid var(--hairline);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}
.yb-header::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 1px;
  background: linear-gradient(90deg, var(--digital-blue) 0%, var(--warm-orange) 34%, rgba(42, 49, 64, 0) 74%);
  opacity: .7;
  pointer-events: none;
}

.yb-header__inner {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 20px;
  width: 100%;
  max-width: var(--shell-max);
  min-height: var(--header-h);
  margin: 0 auto;
  padding: 0 clamp(16px, 3vw, 32px);
}

/* 品牌 */
.yb-header__brand {
  display: grid;
  grid-template-columns: auto auto;
  grid-template-rows: auto auto;
  align-items: center;
  column-gap: 10px;
  text-decoration: none;
  flex: 0 0 auto;
}
.yb-brand__mark {
  grid-row: 1 / 3;
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  background: var(--digital-blue);
  color: #fff;
  font-size: 13px;
  font-weight: 900;
  letter-spacing: .02em;
  border-radius: var(--radius);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, .14);
}
.yb-brand__line {
  font-size: 16px;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: .06em;
  color: var(--cold-white);
}
.yb-brand__tagline {
  font-size: 11px;
  line-height: 1.2;
  letter-spacing: .14em;
  color: var(--index-gray);
}

/* 命令栏 / 导航 */
.yb-commandbar { min-width: 0; }

.yb-commandbar__scroll {
  display: flex;
  align-items: center;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.yb-commandbar__scroll::-webkit-scrollbar { display: none; }

.yb-navlink {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 9px 12px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: .03em;
  color: var(--index-gray);
  white-space: nowrap;
  border-radius: var(--radius);
  transition: color .18s ease, background-color .18s ease;
}
.yb-navlink::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 3px;
  height: 1px;
  background: var(--light-blue);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .22s ease;
}
.yb-navlink:hover { color: #fff; }
.yb-navlink:hover::after { transform: scaleX(1); }
.yb-navlink[aria-current="page"] {
  color: #fff;
  background: var(--digital-blue);
  font-weight: 700;
}
.yb-navlink[aria-current="page"]::after { transform: scaleX(0); }

/* 状态胶囊 */
.yb-live {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 11px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background: rgba(18, 22, 28, .7);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--index-gray);
  white-space: nowrap;
  flex: 0 0 auto;
}
.yb-live__text { display: inline; }
.yb-live__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--pulse-green);
  box-shadow: 0 0 0 3px rgba(76, 255, 138, .16);
  animation: yb-pulse 2.2s ease-in-out infinite;
}
@keyframes yb-pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: .42; transform: scale(.78); }
}

/* 移动菜单按钮 */
.yb-navtoggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  background: rgba(18, 22, 28, .7);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  color: var(--cold-white);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  cursor: pointer;
  transition: border-color .18s ease, background-color .18s ease;
}
.yb-navtoggle:hover { border-color: var(--digital-blue); background: rgba(30, 90, 255, .14); }
.yb-navtoggle__bars { display: grid; gap: 3px; }
.yb-navtoggle__bar {
  display: block;
  width: 14px;
  height: 1px;
  background: currentColor;
  transition: transform .2s ease, opacity .2s ease;
}
.yb-navtoggle[aria-expanded="true"] .yb-navtoggle__bar:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.yb-navtoggle[aria-expanded="true"] .yb-navtoggle__bar:nth-child(2) { opacity: 0; }
.yb-navtoggle[aria-expanded="true"] .yb-navtoggle__bar:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }

/* ==========================================================================
   页面骨架：左侧索引栏 + 右侧内容
   ========================================================================== */
.yb-shell {
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  align-items: start;
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
}

.yb-rail {
  position: sticky;
  top: var(--header-h);
  align-self: start;
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 30px 12px 30px 0;
  border-right: 1px solid var(--hairline);
  background: linear-gradient(180deg, rgba(30, 90, 255, .07), rgba(30, 90, 255, 0) 42%);
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.yb-rail::-webkit-scrollbar { display: none; }

.yb-rail__list { display: grid; gap: 2px; }

.yb-rail__item {
  display: grid;
  grid-template-columns: 22px minmax(0, 1fr);
  align-items: center;
  gap: 5px;
  padding: 7px 6px 7px 8px;
  border-left: 2px solid transparent;
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--index-gray);
  font-size: 12px;
  letter-spacing: .04em;
  text-decoration: none;
  transition: color .18s ease, border-color .18s ease, background-color .18s ease;
}
.yb-rail__item:hover { color: var(--cold-white); background: rgba(245, 247, 255, .04); }
.yb-rail__item.is-active {
  color: #fff;
  border-left-color: var(--pulse-green);
  background: rgba(76, 255, 138, .07);
}
.yb-rail__num { font-family: var(--mono); font-size: 11px; color: var(--index-gray); }
.yb-rail__item.is-active .yb-rail__num { color: var(--pulse-green); }
.yb-rail__text { min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.yb-shell__content {
  min-width: 0;
  padding: 0 clamp(20px, 3.4vw, 56px) 96px;
}

.yb-main {
  display: block;
  min-height: 50vh;
  padding: 40px 0 0;
}

.yb-container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
}

/* ==========================================================================
   网格与列
   ========================================================================== */
.yb-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2vw, 24px);
}
.yb-col-3 { grid-column: span 3; }
.yb-col-4 { grid-column: span 4; }
.yb-col-5 { grid-column: span 5; }
.yb-col-6 { grid-column: span 6; }
.yb-col-7 { grid-column: span 7; }
.yb-col-8 { grid-column: span 8; }
.yb-col-12 { grid-column: span 12; }

/* ==========================================================================
   章节体系
   ========================================================================== */
.yb-section {
  position: relative;
  padding: 56px 0 32px;
  border-top: 1px solid var(--hairline);
}
.yb-section:first-of-type { border-top: 0; padding-top: 24px; }

.yb-section__head {
  display: grid;
  grid-template-columns: minmax(96px, 158px) minmax(0, 1fr);
  align-items: end;
  gap: clamp(16px, 2.4vw, 32px);
  padding-bottom: 20px;
}

.yb-section__num {
  display: block;
  font-family: var(--serif);
  font-weight: 700;
  font-size: clamp(56px, 9vw, 96px);
  line-height: .82;
  letter-spacing: -.03em;
  color: rgba(30, 90, 255, .34);
  user-select: none;
}

.yb-section__title {
  font-size: clamp(24px, 3.2vw, 40px);
  font-weight: 900;
  color: #fff;
}
.yb-section__title .yb-meta { display: block; margin-bottom: 6px; }

.yb-section__excerpt {
  max-width: 40em;
  color: var(--index-gray);
  font-size: 16px;
  line-height: 1.85;
}

.yb-lede {
  font-size: 19px;
  line-height: 1.85;
  font-weight: 500;
  color: var(--cold-white);
  max-width: 36em;
}

.yb-rule {
  height: 1px;
  border: 0;
  background: var(--hairline);
  margin: 28px 0;
}

/* ==========================================================================
   卡片 / 面板 / 标签 / 文字
   ========================================================================== */
.yb-panel {
  position: relative;
  padding: clamp(18px, 2.2vw, 26px);
  background: var(--panel-slate);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  box-shadow: var(--shadow-card);
}
.yb-panel--offset {
  margin-top: -24px;
  margin-left: 24px;
}

.yb-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background: rgba(245, 247, 255, .03);
  color: var(--index-gray);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .06em;
  line-height: 1.7;
  text-decoration: none;
  transition: transform .2s ease, background-color .18s ease, border-color .18s ease, color .18s ease;
}
.yb-tag--orange {
  color: #FFD7C4;
  border-color: rgba(255, 107, 53, .48);
  background: rgba(255, 107, 53, .14);
}
.yb-tag--green {
  color: #C4FFD9;
  border-color: rgba(76, 255, 138, .38);
  background: rgba(76, 255, 138, .09);
}
a.yb-tag:hover,
button.yb-tag:hover,
.yb-tag:hover {
  transform: rotate(-1.5deg);
  border-color: var(--warm-orange);
  color: #fff;
}

.yb-meta {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .04em;
  color: var(--index-gray);
}

.yb-vertical {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--index-gray);
  text-transform: uppercase;
}

/* ==========================================================================
   按钮
   ========================================================================== */
.yb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background: transparent;
  color: var(--cold-white);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .04em;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .18s ease, border-color .18s ease, color .18s ease, transform .18s ease;
}
.yb-btn:hover {
  border-color: var(--digital-blue);
  background: rgba(30, 90, 255, .14);
  color: #fff;
}
.yb-btn:active { transform: translateY(1px); }

.yb-btn--primary {
  background: var(--digital-blue);
  border-color: var(--digital-blue);
  color: #fff;
}
.yb-btn--primary:hover {
  background: var(--digital-blue-deep);
  border-color: var(--digital-blue-deep);
}

.yb-btn--ghost {
  border-color: transparent;
  color: var(--light-blue);
}
.yb-btn--ghost:hover {
  border-color: var(--hairline);
  background: rgba(245, 247, 255, .04);
  color: #fff;
}

/* ==========================================================================
   面包屑
   ========================================================================== */
.yb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 26px;
  padding: 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--index-gray);
  list-style: none;
}
.yb-breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.yb-breadcrumb__item + .yb-breadcrumb__item::before {
  content: "/";
  color: var(--hairline);
}
.yb-breadcrumb__item a { color: var(--light-blue); }
.yb-breadcrumb__item a:hover { color: #fff; }

/* ==========================================================================
   图片容器（页面阶段放置图片）
   ========================================================================== */
.yb-figure {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background-color: var(--panel-slate);
  background-image:
    radial-gradient(120% 90% at 12% 0%, rgba(30, 90, 255, .24) 0%, rgba(30, 90, 255, 0) 62%),
    linear-gradient(rgba(245, 247, 255, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245, 247, 255, .06) 1px, transparent 1px);
  background-size: 100% 100%, 32px 32px, 32px 32px;
}
.yb-figure--wide { aspect-ratio: 16 / 9; }
.yb-figure--tall { aspect-ratio: 3 / 4; }
.yb-figure--square { aspect-ratio: 1 / 1; }

.yb-figure img,
.yb-figure picture,
.yb-figure video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.yb-figure--orange::before {
  content: "";
  position: absolute;
  top: 14px;
  right: 14px;
  width: 26px;
  height: 8px;
  background: var(--warm-orange);
  border-radius: 1px;
  opacity: .9;
}

/* ==========================================================================
   网格底纹装饰层
   ========================================================================== */
.yb-texture {
  background-image:
    linear-gradient(rgba(245, 247, 255, .06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245, 247, 255, .06) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* ==========================================================================
   滚动显现
   ========================================================================== */
html[data-js="on"] [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity .52s cubic-bezier(.2, .7, .3, 1),
    transform .52s cubic-bezier(.2, .7, .3, 1);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}
html[data-js="on"] [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ==========================================================================
   页脚
   ========================================================================== */
.yb-footer {
  margin-top: 72px;
  border-top: 1px solid var(--hairline);
  background: var(--panel-slate);
  background-image: linear-gradient(180deg, rgba(30, 90, 255, .06), rgba(30, 90, 255, 0) 220px);
}

.yb-footer__inner {
  display: grid;
  grid-template-columns: minmax(210px, 1fr) minmax(0, 2.6fr);
  gap: clamp(28px, 4vw, 56px);
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px clamp(16px, 3vw, 32px) 30px;
}

.yb-footer__brandcol { min-width: 0; }
.yb-footer__brand {
  font-size: 22px;
  font-weight: 900;
  letter-spacing: .06em;
  color: #fff;
  margin: 0 0 8px;
  max-width: none;
}
.yb-footer__brandline {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--index-gray);
  margin: 0 0 14px;
  max-width: none;
}
.yb-footer__since {
  font-size: 13px;
  line-height: 1.8;
  color: var(--index-gray);
  max-width: 24em;
  margin: 0;
}

.yb-footer__cols {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 24px;
}
.yb-footer__col { min-width: 0; }
.yb-footer__title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .2em;
  color: var(--index-gray);
  text-transform: uppercase;
}
.yb-footer__list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.yb-footer__list a {
  display: inline-block;
  color: var(--cold-white);
  font-size: 14px;
  line-height: 1.6;
  border-bottom: 1px solid transparent;
  transition: color .18s ease, border-color .18s ease;
}
.yb-footer__list a:hover {
  color: var(--light-blue);
  border-bottom-color: var(--light-blue);
}

.yb-footer__contact {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(16px, 3vw, 32px) 26px;
}
.yb-footer__contactline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 16px;
  padding: 16px 18px;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  background: rgba(10, 12, 16, .6);
  font-size: 13px;
  color: var(--cold-white);
}
.yb-footer__label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--index-gray);
}
.yb-footer__addr {
  color: var(--index-gray);
  font-size: 13px;
}

.yb-copy {
  padding: 6px 11px;
  border: 1px solid rgba(30, 90, 255, .34);
  border-radius: var(--radius);
  background: rgba(30, 90, 255, .12);
  color: var(--light-blue);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .02em;
  line-height: 1.5;
  cursor: pointer;
  transition: background-color .18s ease, border-color .18s ease, color .18s ease;
}
.yb-copy:hover { background: rgba(30, 90, 255, .24); color: #fff; }
.yb-copy.is-done {
  color: var(--pulse-green);
  border-color: rgba(76, 255, 138, .42);
  background: rgba(76, 255, 138, .1);
}

.yb-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px clamp(16px, 3vw, 32px) 36px;
  border-top: 1px solid var(--hairline);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--index-gray);
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1024px) {
  .yb-shell {
    grid-template-columns: minmax(0, 1fr);
  }
  .yb-rail {
    position: sticky;
    top: var(--header-h);
    z-index: 30;
    height: auto;
    padding: 0;
    border-right: 0;
    border-bottom: 1px solid var(--hairline);
    background: rgba(10, 12, 16, .95);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
  }
  .yb-rail__list {
    display: flex;
    align-items: center;
    gap: 4px;
    overflow-x: auto;
    padding: 8px clamp(12px, 3vw, 24px);
    scrollbar-width: none;
    -ms-overflow-style: none;
  }
  .yb-rail__list::-webkit-scrollbar { display: none; }
  .yb-rail__item {
    grid-template-columns: auto auto;
    gap: 6px;
    padding: 6px 10px;
    border-left: 0;
    border-bottom: 2px solid transparent;
    border-radius: var(--radius) var(--radius) 0 0;
    white-space: nowrap;
  }
  .yb-rail__item.is-active {
    border-left-color: transparent;
    border-bottom-color: var(--pulse-green);
    background: rgba(76, 255, 138, .06);
  }
  .yb-rail__text { overflow: visible; text-overflow: clip; }
}

@media (max-width: 900px) {
  .yb-header__inner {
    grid-template-columns: minmax(0, 1fr) auto auto;
    gap: 10px;
    padding: 0 16px;
  }
  .yb-navtoggle { display: inline-flex; order: 3; }
  .yb-live { order: 2; padding: 8px; font-size: 0; gap: 0; }
  .yb-live__text { display: none; }
  .yb-live__dot { width: 7px; height: 7px; }

  .yb-commandbar {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 40;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    background: var(--panel-slate);
    border-bottom: 1px solid var(--hairline);
    transition: max-height .3s ease, visibility .3s linear;
  }
  .yb-commandbar[data-open] {
    max-height: min(72vh, 520px);
    overflow-y: auto;
    visibility: visible;
    box-shadow: var(--shadow-drawer);
  }
  .yb-commandbar__scroll {
    display: block;
    overflow: visible;
    padding: 6px 0;
  }
  .yb-navlink {
    display: block;
    padding: 15px 22px;
    font-size: 15px;
    letter-spacing: .05em;
    border-bottom: 1px solid rgba(42, 49, 64, .7);
    border-radius: 0;
  }
  .yb-navlink:last-child { border-bottom: 0; }
  .yb-navlink::after { display: none; }
  .yb-navlink[aria-current="page"] {
    background: rgba(30, 90, 255, .16);
    color: #fff;
    box-shadow: inset 3px 0 0 var(--warm-orange);
  }
  .yb-navlink:hover { background: rgba(245, 247, 255, .04); }

  .yb-shell__content { padding: 0 18px 72px; }

  .yb-grid { grid-template-columns: minmax(0, 1fr); }
  .yb-col-3, .yb-col-4, .yb-col-5, .yb-col-6, .yb-col-7, .yb-col-8, .yb-col-12 {
    grid-column: span 1;
  }

  .yb-section { padding: 40px 0 24px; }
  .yb-section__head {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
    gap: 8px;
  }
  .yb-section__num { line-height: .9; }

  .yb-panel--offset { margin-top: 0; margin-left: 0; }

  .yb-footer { margin-top: 48px; }
  .yb-footer__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 32px;
    padding: 40px 18px 26px;
  }
  .yb-footer__cols {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px 20px;
  }
  .yb-footer__contact { padding: 0 18px 24px; }
  .yb-footer__contactline { padding: 14px; }
  .yb-footer__legal { padding: 16px 18px 32px; }
}

@media (max-width: 520px) {
  body { font-size: 16px; }
  .yb-lede { font-size: 17px; }
  .yb-brand__tagline { display: none; }
  .yb-brand__mark { width: 34px; height: 34px; font-size: 12px; }
  .yb-footer__cols { grid-template-columns: minmax(0, 1fr); }
  .yb-footer__contactline { flex-direction: column; align-items: flex-start; }
  .yb-copy { width: 100%; text-align: left; }
}

/* ==========================================================================
   无障碍 / 动效偏好
   ========================================================================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
  }
  .yb-live__dot { animation: none; }
  html[data-js="on"] [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .yb-tag:hover,
  a.yb-tag:hover,
  button.yb-tag:hover { transform: none; }
}

@media print {
  .yb-header, .yb-rail, .yb-footer, .yb-skip { display: none; }
  body { background: #fff; color: #000; }
}